Glowworm 75/80 boiler. Fan stays on , water does not get hot enough?

Recently had a loud noise coming from my boiler then the fan has stopped completely (not sure if it is a swiftflow 75 or 80). Opened the casing up and checked the fan, seems to be ok. Changed a fuse in the pcb board and the fan started again but it spins continuosly. The water does not heat up very hot, the front of the boiler gets very hot and there sometimes is a smell coming from it. Before the fan stopped there was no trouble with water temp or any smell. Can any one help?